Helina obscurisquama obscurisquama (Stein)

Michelsen, Verner, 2023, Macaronesian Muscidae (Diptera). IV. The genus Helina Robineau-Desvoidy, and description of the male of Spilogona maderensis Michelsen, Zootaxa 5293 (2), pp. 251-276 : 254-257

2. Helina obscurisquama obscurisquama (Stein)

( Figs 2A–C , 3A–C , 4A )

Mydaea obscurisquama Stein ; Becker 1908a: 96 ff. (Tenerife).

Mydaea (Spilaria) obscurisquama Stein ; Santos Abréu 1976: 124 ff., fig. 19 (p.p., La Gomera).

Helina obscurisquama (Stein) ; Hennig 1958: 202 (Tenerife); Kirchberg 1967: 334 (p.p., Tenerife,?Hierro); Hennig 1978: 4 (Canary Is.); Baéz 1983: 180 ff., pl. 1 fig. 2, pl. 2 figs 3, 9 (p.p., Tenerife, La Gomera,?Hierro);

Material examined. CANARY ISLANDS: TENERIFE: Aguamansa , 1♀ 17.vii.1931 ( R. Frey); Valle de Santiago , 1000m, 1♁ 20‒21.ii.1950 (H. Lindberg); La Esperanza , Pico de las Flores, 1200m, 1♁ 10.iv.1993 (M. Koponen); Mt Grande , Esperanza , 1400m, 2♁, 1♀ 28.vii.1989 (Olsen, Skule & Stadel); Realejo Alto , 400m, 1♁ 29.vii.1989 (Olsen, Skule & Stadel); La Zarza, 2♁, 1♀ 15‒20.i.2006 ( V. Michelsen); Carrizal Alto, 28°19´N 16°51´W, 640‒ 730m, 1♁ 30.i‒3.ii.2016 ( V. Michelsen). LA GOMERA: El Rincón, 1♁ 20.xi.2002 ( V. Michelsen); La Palmita, 1♀ 10.i.2006 ( V. Michelsen); Agulo, Lepe, 7♁ 12‒13.i.2006 ( V. Michelsen); Los Loros, 28°09´N 17°16´W, 500‒ 770m, 4♀ 1‒7.ii.2008, 3♀ 18‒23.i.2012 ( V. Michelsen); Epina, 28°10´N 17°18´W, 600‒670m, 1♁ 13‒16.i.2019 ( V. Michelsen); Lomito Fragoso, 28°07´N 17°10´W, 220‒250m, 1♀ 19‒24.i.2019 ( V. Michelsen) .

Description. Medium to large sized, wing length 5.7–8.0 mm. Male: Ground colour of head, body and appendages wholly dark; thorax and abdomen subshining through thin cover of bluish-grey pruinosity, in posterior views with vague dark pattern of four scutal stripes; abdomen ( Fig. 2B ) with paired oval abdominal marks on tergites III and IV along with a narrow mid-dorsal stripe; calypteres brown, same colour as wing base; only cross-vein r-m shadowed. Eyes with long and dense pile. Longest aristal branches c. 1.25 times as long as width of postpedicel. Frons ( Fig. 2A ) at narrowest point at the most half as wide as ocellar tubercle; frontal vitta at this point more or less suppressed by fronto-orbital plates. Dorsocentral setae 2 + 4; presutural acrostichal field with fine setulae only in multible, irregular rows; notopleuron without setulae; prealar seta much shorter than posterior notopleural seta; katepisternal setae 2 + 2; meron with fine setulae beneath posterior spiracle and along hind margin; scutellum with setulae immediately below lateral setae as well as at latero-ventral margin. Vein C bare dorsally. Fore tibia with 1 p seta; mid tibia with 0 ad and 3 p setae; hind femur ( Fig. 2C ) with complete row of av setae being very long on subdistal half and a finer row of pv setae confined to distal quarter; hind tibia with 3–4 fine av and 2 ad setae and with a comb of fine p setae on subbasal half. Abdomen ( Fig. 2A ) broadly ovoid; sternite V and hypopygium as in Figs 3A–C . Female: Apart from usual sexual differences of the head and abdomen differing from the male by the thorax covered in brownish grey pruinosity in contrast to the bluish tinge retained on the abdomen ( Fig. 4A ), the paired dark marks on tergites III and IV blurred by tessellating dark reflections, eye pile shorter and less dense, hind femur without longish pv setae on distal part and hind tibia without row of fine p setae.

Distribution. Endemic to Tenerife and La Gomera. The subspecific status of the population living on Hierro is presently unclarified.

Figures

FIGURE 2. Helina obscurisquama obscurisquama (Stein) (A–C), H. grancanariae sp. nov. (D–F), males. Head, frontal (A, D); abdomen (B, E); right femur and tibia (C, F).

FIGURE 3. Helina obscurisquama obscurisquama (Stein) (A–C), H. grancanariae sp. nov. (D–F), male terminalia. Sternite V (A, D); hypopygium, caudal (B, E) and lateral (C, F). Same scale.

FIGURE 4. Helina obscurisquama obscurisquama (Stein) (A), H. obscurisquama pseudonivalis (Santos Abréu) (B), females. Abdomen (A, B).